1. Field of the Invention
The present invention relates to an electronic survey instrument which is controlled by computer programs.
2. Related Background Art
Recently, as for various survey instruments having distance and angle measuring functions, many electronic survey instruments which are controlled based on a computer program have been proposed.
In the conventional electronic survey instruments, since a data recorder connected to a survey instrument records survey data, if the power source therefor is cut off during surveying or after completion, measurement data are stored on a recording portion in a data recorder. However, a display image and count values, displayed on a display device of the survey instrument, are also cleared due to a power-off operation. Hence, when the system is resumed by the next power-on operation, a display image must be updated and a predetermined count value must be loaded.